Emission trends, pledges and their implementation

摘要: This chapter presents an update, based on the scientific literature, of following critical topics: -- current (2010 global) emissions greenhouse gases; projected (to 2020) gases under a business-as-usual (BaU) scenario; projections gas four different sets assumptions regarding implementation national pledges to reduce emissions; extent which parties are positioned implement their pledges, in light policy portfolios and plausible macroeconomic trends offsets. The estimated emission level 2020 scenario is 1 gigatonne carbon dioxide equivalent (GtCO2e) higher compared last year's gap report. While levels for strict-rules cases by roughly GtCO2e (unconditional) comparable (conditional), associated with two lenient-rules lower GtCO2e, as estimates. These changes mainly due decisions surpluses made countries during Doha climate negotiations downward revisions double counting They illustrate that increasing stringency through can help cases. However, they do not reflect increase ambition or action, but represent move towards stricter accounting rules. To illustrate, report, were 3 than those cases, whereas this year around 2 (conditional). While previous reports assumed full pledge implementation, we also explore 13 parties, 72 percent global emissions, already track where further offsets likely be required.